Dataset Information

Nondaily Smokers' Changes in Cigarette Consumption With Very Low-Nicotine-Content Cigarettes: A Randomized Double-blind Clinical Trial.

ABSTRACT:

Importance

The US Food and Drug Administration is considering limiting cigarettes to very low nicotine levels. Cigarette consumption of nondaily intermittent smokers (ITS), who compose one-third of US adult smokers, could feasibly increase or could be unaffected if their smoking is not motivated by nicotine seeking.

Objective

To compare cigarette consumption in ITS receiving very low-nicotine-content cigarettes (VLNCCs) or identical normal-nicotine-content cigarettes (NNCCs).

Design, setting, and participants

This randomized double-blind clinical trial was conducted from June 2015 to July 2017 at a single US site. Volunteer ITS not planning to quit were recruited via media. Overall, 297 individuals enrolled, and 238 were randomized. Analyses were intent-to-treat.

Interventions

After a 2-week baseline of smoking their own brand of cigarettes provided gratis, ITS were randomized to VLNCCs or NNCCs for 10 weeks.

Main outcomes and measures

The number of cigarettes per day (CPD) was assessed by real-time reporting, timeline follow-back reports, and cigarette butt counts. The primary outcome was change in CPD from baseline to weeks 9 to 10 of intervention, adjusting for baseline CPD.

Results

The mean (SD) age of the 238 randomized participants was 37.9 (13.8) years. Of 238 participants, 108 (45%) were men. At baseline, the mean (SD) CPD was 3.1 (2.9). In intent-to-treat analyses using multiple imputation to address missing data, the VLNCC group had a mean decrease of 1.6 CPD (95% CI, 1.1-2.0; 51% of baseline) vs 0.05 decrease with NNCCs (95% CI, -0.5 to 0.4; 2% of baseline). Treatment group differences were not materially moderated by sex, race/ethnicity, or history of daily smoking. Cheating with conventional cigarettes, inferred from cotinine assays, was more common in the VLNCC group (OR, 2.95; 95% CI, 1.54-5.66), but sensitivity analyses showed significant VLNCC effects among the compliant participants as well. In longitudinal analysis of CPD over time with random intercept and slope, the VLNCC and NNCC groups differed significantly in both linear (-0.15; 95% CI, -0.22 to -0.08; P < .001) and quadratic (0.0026; 95% CI, 0.0010-0.0042; P = .002) trends: CPD dropped by 43.8% in the VLNCC group over 4 weeks, then leveled off thereafter. Abstinence (intent-to-treat, biochemically verified) in weeks 9 to 10 postrandomization did not differ significantly by treatment group (VLNCC, 10.2% vs NNNC, 5.0%; P = .28).

Conclusions and relevance

Switching to VLNCCs caused substantial smoking reduction among ITS but did not significantly increase abstinence. Response to a VLNCC intervention suggests that nicotine-seeking motivates ITS' smoking.

Trial registration

ClinicalTrials.gov Identifier: NCT02228824.

SUBMITTER: Shiffman S

PROVIDER: S-EPMC6233810 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:IntroductionThe Food and Drug Administration issued an advanced notice of proposed rulemaking for setting a product standard for nicotine levels in cigarettes, with an emphasis on minimally or non-addicting very low nicotine content (VLNC).MethodsA 33 week, two-arm, double-blind randomized trial conducted in Hershey, Pennsylvania, USA and Washington, DC, USA included adult daily cigarette smokers (≥5 cigarettes per day) with less than a college degree, and who had no plans to quit within the next six months. Participants were randomized to either reduced nicotine content (RNC) study cigarettes tapered every three weeks to a final VLNC (0.2 mg/cigarette) for six weeks or to usual nicotine content (UNC) study cigarettes (11.6 mg/cigarette). Outcomes included acceptability of study cigarettes measured by attrition (primary outcome), compliance, reduction in cigarette dependence and tobacco biomarkers, and post-intervention cessation.ResultsThe RNC (n = 122) versus UNC (n = 123) group had higher attrition (adjusted Hazard Ratio 3.4; 95% confidence interval [CI] 1.99 to 5.81). At the end of the intervention, cotinine levels were 50% lower in the RNC group (mean group difference -137 ng/mL; 95% CI -172, -102). The RNC group smoked fewer CPD (-4.1; 95% CI -6.44, -1.75) and had lower carbon monoxide levels (-4.0 ppm; 95% CI -7.7, -0.4). Forty seven percent (29/62) of the RNC group were biochemically-confirmed compliant with smoking VLNC cigarettes (mean cotinine = 8.9 ng/ml). At three month follow-up, only compliant VLNC smokers quit with an assisted quit attempt (N = 6/22, 27%).ConclusionsThis study supports a VLNC standard in cigarettes.ImplicationsDifferential dropout and noncompliance indicate some smokers had difficulty transitioning to cigarettes with reduced nicotine. These smokers will benefit from supplemental nicotine in medicinal or noncombustible tobacco products if a nicotine reduction standard is established. Other smokers successfully transitioned to very low nicotine content cigarettes exclusively and substantially reduced their exposure to nicotine.

Project description:ImportanceThis study is part of a programmatic effort evaluating the effects of reducing nicotine content of cigarettes to minimally addictive levels.ObjectiveTo examine whether very low-nicotine-content (VLNC) cigarettes decrease smoking rates and dependence severity among smokers with psychiatric disorders or socioeconomic disadvantage.Design, setting, and participantsThese 3 randomized clinical trials were performed at the University of Vermont, Brown University, and Johns Hopkins University between October 2016 and September 2019. Participants received 12 weeks of exposure to study cigarettes with nicotine content ranging from levels representative of commercial cigarettes (15.8 mg nicotine/g tobacco) to less than a hypothesized addiction threshold (2.4 mg/g and 0.4 mg/g). Daily smokers from 3 at-risk populations participated: individuals with affective disorders, exemplifying smokers with mental illness; individuals with opioid use disorder, exemplifying smokers with substance use disorders; and women with high school educations or less, exemplifying smokers with socioeconomic disadvantage. Data were analyzed from September 2019 to July 2020.InterventionsRandom assignment to 1 of 3 study cigarettes provided weekly at no cost for 12 weeks.Main outcomes and measuresThe primary outcome was between-group differences in mean total cigarettes smoked daily (CPD) during week 12; secondary outcomes included CPD for study and nonstudy cigarettes and dependence severity across weeks analyzed using analysis of covariance, random coefficients growth modeling, or repeated measures analysis of variance.ResultsA total of 775 participants were included (mean [SD] age, 35.59 [11.05] years; 551 [71.10%] women [owing to 1 population being exclusively women]); participants smoked a mean (SD) of 17.79 (9.18) CPD at study intake. A total of 286 participants were randomized to 0.4 mg/g, 235 participants were randomized to 2.4 mg/g, and 254 participants were randomized to 15.8 mg/g. Participants randomized to VLNC cigarettes had decreased mean [SEM] total CPD during week 12 across populations (Cohen d = 0.61; P < .001). At week 12, mean (SEM) CPD decreased to 17.96 (0.98) CPD in the 0.4 mg/g group and to 19.53 (1.07) CPD in the 2.4 mg/g group, both of which were significantly different from the 15.8 mg/g group (25.08 [1.08] CPD at week 12) but not each other (0.4 mg/g adjusted mean difference: -7.54 [95%CI, -9.51 to -5.57]; 2.4 mg/g adjusted mean difference: -5.34 [95% CI, 7.41 to -3.26]). Several secondary outcomes differed across populations randomized to VLNCs, including mean total CPD across weeks, with linear trends lower in participants receiving 0.4 mg/g (-0.28 [95%CI, -0.39 to -0.18]; P < .001) and 2.4 mg/g (-0.13 [95%CI, -0.25 to -0.01]; P < .001) doses compared with those receiving the 15.8 mg/g dose (0.30 [95% CI, 0.19 to 0.41]). Fagerström Test of Nicotine Dependence mean total scores were significantly lower in participants who received VLNCs (Cohen d = 0.12; P < .001), with those who received the 0.4 mg/g dose (mean [SD] score, 3.99 [0.06]; P < .001 vs 15.8 mg/g) or 2.4 mg/g dose (mean [SD] score, 4.07 [0.06]; P = .01 vs 15.8 mg/g) differing from those who received the 15.8 mg/g dose (mean [SD] score, 4.31 [0.06]) but not from each other.Conclusions and relevanceThese findings demonstrate that decreasing the nicotine content of cigarettes to very low levels reduced smoking rate and nicotine-dependence severity in these high-risk populations, effects that may facilitate successful cessation.Trial registrationClinicalTrials.gov Identifiers: NCT02232737, NCT02250664, NCT02250534.

Project description:IntroductionThe US Food and Drug Administration is considering implementing a reduced-nicotine standard for cigarettes. Given the high rate of smoking among people with serious mental illness (SMI), it is important to examine the responses of these smokers to very low nicotine content (VLNC) cigarettes.MethodsThis trial compared the effects of VLNC (0.4 mg nicotine/g tobacco) and normal nicotine content cigarettes (15.8 mg/g) over a 6-week period in non-treatment-seeking smokers with schizophrenia, schizoaffective disorder, or bipolar disorder (n = 58). Linear regression was used to examine the effects of cigarette condition on cigarettes per day, subjective responses, nicotine and tobacco toxicant exposure, craving, withdrawal symptoms, and psychiatric symptoms.ResultsAt week 6, participants in the VLNC condition smoked fewer cigarettes per day, had lower breath carbon monoxide levels, lower craving scores, and rated their study cigarettes lower in satisfaction, reward, enjoyment, and craving reduction than those in the normal nicotine content condition (ps < .05). Week 6 psychiatric and extrapyramidal symptoms did not differ by condition, except for scores on a measure of parkinsonism, which were lower in the VLNC condition (p < .05). There were no differences across conditions on total nicotine exposure, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, withdrawal symptoms, or responses to abstinence.ConclusionsThese results suggest that a reduced-nicotine standard for cigarettes would reduce smoking among smokers with SMI. However, the lack of effect on total nicotine exposure indicates VLNC noncompliance, suggesting that smokers with SMI may respond to a reduced-nicotine standard by substituting alternative forms of nicotine.ImplicationsResults from this trial suggest that a reduced-nicotine standard for cigarettes would reduce smoking rates and smoke exposure in smokers with SMI, without increasing psychiatric symptoms. However, noncompliance with VLNC cigarettes was observed, suggesting that these smokers might respond to a reduced-nicotine standard by substituting alternative forms of nicotine.

Project description:BackgroundThere is considerable debate about the benefits and risks of electronic cigarettes (ECs). To better understand the risk-benefit ratio of ECs, more information is needed about net nicotine consumption and toxicant exposure of cigarette smokers switching to ECs.MethodsForty cigarette smokers (?1 year of smoking) interested in switching to ECs but not necessarily quitting smoking were enrolled in a 4-week observational study and provided an e-Go C non-variable battery and refillable atomizers and choice of eight flavors in 12 or 24 mg nicotine dosage. Measurement of urinary cotinine (metabolite of nicotine), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL; a pulmonary carcinogen), and eight volatile organic compounds (VOCs) that are toxic tobacco smoke constituents was conducted at baseline and week 4.ResultsAll participants with follow-up data (92.5%) reported using the study EC. Of the 40 smokers, 16 reported no cigarettes at week 2 (40%) and six continued to report no cigarettes at week 4 (15%). Change in nicotine intake over the 4 weeks was non-significant (p = .90). Carbon monoxide (p < .001), NNAL (p < .01) and metabolites of benzene (p < .01) and acrylonitrile (p = .001) were significantly decreased in the study sample. Smokers switching exclusively to ECs for at least half of the study period demonstrated significant reductions in metabolites of ethylene oxide (p = .03) and acrylamide (p < .01).ConclusionSmokers using ECs over 4 weeks maintained cotinine levels and experienced significant reductions in carbon monoxide, NNAL, and two out of eight measured VOC metabolites. Those who switched exclusively to ECs for at least half of the study period significantly reduced two additional VOCs.ImplicationsThis study extends current literature by measuring change in smoking dependence and disease-associated biomarkers, NNAL and a panel of eight common VOCs that are toxic tobacco smoke constituents in smokers who switch to ECs. The findings support the idea of harm reduction, however some levels of toxicant exposure are still of clinical concern, particularly for dual users. Extrapolation of these results must be careful to separate the different toxic exposure results for exclusive switchers versus dual cigarette + EC users, and not to equate harm reduction with the idea that using ECs is harmless.

Project description:IntroductionBecause 30% of cigarettes sold in the United States are characterized as menthol cigarettes, it is important to understand how menthol preference may affect the impact of a nicotine reduction policy.MethodsIn a recent trial, non-treatment-seeking smokers were randomly assigned to receive very low nicotine cigarettes (VLNC; 0.4 mg nicotine/g tobacco) or normal nicotine cigarettes (NNC; 15.5 mg/g) for 20 weeks. On the basis of preference, participants received menthol or non-menthol cigarettes. We conducted multivariable regression analyses to examine whether menthol preference moderated the effects of nicotine content on cigarettes per day (CPD), breath carbon monoxide (CO), urinary total nicotine equivalents (TNE), urinary 2-cyanoethylmercapturic acid (CEMA), and abstinence.ResultsAt baseline, menthol smokers (n = 346) reported smoking fewer CPD (14.9 vs. 19.2) and had lower TNE (52.8 vs. 71.6 nmol/mg) and CO (17.7 vs. 20.5 ppm) levels than non-menthol smokers (n = 406; ps < .05). At week 20, significant interactions indicated that menthol smokers had smaller treatment effects than non-menthol smokers for CPD (-6.4 vs. -9.3), TNE (ratio of geometric means, 0.22 vs. 0.10) and CEMA (ratio, 0.56 vs. 0.37; ps < .05), and trended toward a smaller treatment effect for CO (-4.5 vs. -7.3 ppm; p = .06). Odds ratios for abstinence at week 20 were 1.88 (95% confidence interval [CI] = 0.8 to 4.4) for menthol and 9.11 (95% CI = 3.3 to 25.2) for non-menthol VLNC smokers (p = .02) relative to the NNC condition.ConclusionsAlthough menthol smokers experienced reductions in smoking, toxicant exposure, and increases in quitting when using VLNC cigarettes, the magnitude of change was smaller than that observed for non-menthol smokers.ImplicationsResults of this analysis suggest that smokers of menthol cigarettes may respond to a nicotine reduction policy with smaller reductions in smoking rates and toxicant exposure than would smokers of non-menthol cigarettes.